package yu.zhou.njupt.pdsmigration.utils;


/**
 * @author yu.zhou
 * 
 */
public class StringUtil {
    
    public  static String getPlaceHolderStr(int num) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < num; i++) {
            sb.append("?,");
        }
        String str = sb.toString();
        return str.substring(0, str.lastIndexOf(","));
    }
    
}
